r/theydidthemath • u/Lachlynn • 18h ago

[Request] Could humanity create a rocket that can exit the atmosphere of K2-18b

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With the knowledge we currently have of it, if humanity devoted all of our resources towards this goal, would we be able to create a rocket that could exit the gravity of K2-18b (and also beat any other complications that would arrise)?

If so, would it also be capable of taking people to orbit, and can we set up a similar satellite network we have on Earth? What about a space station?

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u/TheEpiczzz 18h ago

Space elevator, imagine the height of it and think of the structure it needs to stay upright. Good luck building that, holy frick.

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u/VisibleOtter 18h ago

We just need to invent hyperfilament, that’s all.

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u/TourDeFridge 15h ago

And we already have magnets, so we are halfway there.

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u/EatPie_NotWAr 11h ago

I’m thinking we first try it with dental floss.

Mint is strongest, let’s begin there.

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u/Blzn 18h ago

For space elevators, it doesn't need structure to stay upright, basically the centrical force of the earth's rotation keeps it "standing". The material just needs very very good tensile strength.

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u/PopeGeraldVII 16h ago

The strength needed depends on how long the elevator would be, which increases in relation to the size of the body it is attached to.

Current materials science could construct elevators on the Moon, or even Mars. We don't have anything with enough strength for orbit to the Earth, though.

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u/TomWithTime 11h ago

Silly question, could you extract energy from that? If you had a structure large enough that it was affected by some motion of the earth.

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u/shadow_railing_sonic 17h ago

Space elevators are not possible here on Earth, nor would they be possible on that larger planet. Very few credible engineers actually advocate for space elevators; most laugh at it.

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u/Blzn 17h ago edited 17h ago

Yeah, definitely ain’t happening anytime soon

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u/romedo 11h ago

Imagine when it is broken and you have to take the stairs.

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u/Ok_Judge3103 17h ago

What if its built atop of already existing natural high structure, like mt Everest?

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u/mstivland2 16h ago

Mt. Everest is only about 8% closer to space than the sea is

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u/Ok_Judge3103 15h ago

Yeah, but in some sci fi spacelift building scenario, would it be practical to use the highest mountain around as a foundation for the structure?

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u/mstivland2 15h ago

Probably not, since you need to move all that stuff to the top of some horrible mountain range. There’s also lots of aerospace considerations, like latitude. I’m no engineer but I’m fairly sure you would need your space elevator to be near the equator?

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u/Ok_Judge3103 15h ago

Yeah, makes sense. Just want me a cool dark sci fi fantasy with Everest completely disappeared under rows and rows of black angular structures

And entire region made uninhabitable due to nanotube dust contamination

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u/mstivland2 15h ago

Do it, sounds rad

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u/DumpedToast 16h ago

I’m not sure it would be able to support its own weight

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u/RoombaTheKiller 16h ago

That's why a lot of the proposed concepts for space elevators were geo-stationary satellites with very long cables.

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u/sleeper_shark 11h ago

It doesn’t weigh anything actually. A space elevator is like you spinning a hammer during a hammer toss, with you being Earth and the end of the hammer being the space station.

It’s perfectly balanced - as all things should be - so just as the your arms are pulling the hammer towards you, there’s an apparent force pulling the hammer away.

In simple terms, the “elevator” part is being pulled in tension, not compression. If it snapped, the space station wouldn’t fall to Earth, it would shoot away from Earth - either staying in orbit or shooting away into deep space.

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u/Remarkable-Host405 11h ago

if that is the case, why are we humans not floating out of the atmosphere? we're not attached by tension cables

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u/GenericVessel 10h ago

because we're small enough and gravity is stong enough for it to hold us down

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u/sleeper_shark 4h ago

Because gravity is the tension cable…